diff options
| -rw-r--r-- | compiler/rustc_metadata/src/rmeta/encoder.rs | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs index eaac3694f1f..b0ec605a85f 100644 --- a/compiler/rustc_metadata/src/rmeta/encoder.rs +++ b/compiler/rustc_metadata/src/rmeta/encoder.rs @@ -2389,6 +2389,11 @@ impl<D: Decoder> Decodable<D> for EncodedMetadata { #[instrument(level = "trace", skip(tcx))] pub fn encode_metadata(tcx: TyCtxt<'_>, path: &Path, ref_path: Option<&Path>) { + // Since encoding metadata is not in a query, and nothing is cached, + // there's no need to do dep-graph tracking for any of it. + tcx.dep_graph.assert_ignored(); + + // Generate the metadata stub manually, as that is a small file compared to full metadata. if let Some(ref_path) = ref_path { let _prof_timer = tcx.prof.verbose_generic_activity("generate_crate_metadata_stub"); @@ -2401,11 +2406,14 @@ pub fn encode_metadata(tcx: TyCtxt<'_>, path: &Path, ref_path: Option<&Path>) { is_stub: true, }); header.position.get() - }); + }) } + let _prof_timer = tcx.prof.verbose_generic_activity("generate_crate_metadata"); + let dep_node = tcx.metadata_dep_node(); + // If the metadata dep-node is green, try to reuse the saved work product. if tcx.dep_graph.is_fully_enabled() && let work_product_id = WorkProductId::from_cgu_name("metadata") && let Some(work_product) = tcx.dep_graph.previous_work_product(&work_product_id) @@ -2422,12 +2430,6 @@ pub fn encode_metadata(tcx: TyCtxt<'_>, path: &Path, ref_path: Option<&Path>) { return; }; - let _prof_timer = tcx.prof.verbose_generic_activity("generate_crate_metadata"); - - // Since encoding metadata is not in a query, and nothing is cached, - // there's no need to do dep-graph tracking for any of it. - tcx.dep_graph.assert_ignored(); - if tcx.sess.threads() != 1 { // Prefetch some queries used by metadata encoding. // This is not necessary for correctness, but is only done for performance reasons. @@ -2441,6 +2443,8 @@ pub fn encode_metadata(tcx: TyCtxt<'_>, path: &Path, ref_path: Option<&Path>) { ); } + // Perform metadata encoding inside a task, so the dep-graph can check if any encoded + // information changes, and maybe reuse the work product. tcx.dep_graph.with_task( dep_node, tcx, @@ -2461,7 +2465,7 @@ pub fn encode_metadata(tcx: TyCtxt<'_>, path: &Path, ref_path: Option<&Path>) { ); root.position.get() - }); + }) }, None, ); |